1. Do you run on the road, and if so, do you run on the same side of the road all the time? Most roads are slightly higher in the middle, and that imbalance can wreck the hip on the higher side of the road. I know of runners who have ruined themselves because of this. If its not your IT band and X-rays don't show anything, it could be the off-sided impact.

2. Stop running for a while - find something else to do and cross-train while your hip heals. Take up cycling, rowing, dancing, whatever - give it a solid month or three to recover. When you get back on the running program, try to alternate sides of the road, or go run on a a trail or path to keep your joints more evenly impacted. And keep up cross-training - running alone is a great way to injure yourself because of muscle imbalances.

Finally, don't forget to use ice after workouts to calm down inflammation in injured areas - it can have a significant effect on the healing time of the injury.